Fire and burglar alarm system

ABSTRACT

A security system for a building including a circuit having heat detectors responsive to smoke or fire in the building to enable an alarm generator to provide an alarm signal, and an entry circuit having normally open and normally closed entry switches for detecting an unauthorized entry of the building, the entry circuit being energized whenever one of the entry switches is operated to enable the alarm generator to provide a different alarm, and the entry circuit further having a ready indicator for indicating when an entry switch is operated.

United States Patent FIRE SYSTEM [151 3,686,668 Durkee [451 Aug. 22, 1972 [54] FIRE AND BURGLAR ALARM SYSTEM 3,441,929 4/ i969 Coffer etal ..340/409 72 I t 2 3,546,688 12/ 1970 Jensen et ai. ..340/276 X l 1 E 3,487,404 12/1969 Midkifi ..340/276 x [73] Assignee: Thom? Ind ries, In kl 3,401,384 9/1968 Highstone etal ..340/276 son, is. v Primary Examiner-Thomas D. Habecker [22] Assistant Examiner-William M. Wannisky [21] Appl. No.: 16,398 Attorney-Johnson, Dienner, Emrich, Verbeck &

Wagner [52] US. Cl. ..340/420, 340/276, 340/293,

340/227, 340/297 [57] i ABS CT 51 Int. Cl. ..G08b 19/00 A security system for a building including a circuit [58] Field 6: Search ..340/420, 274, 409, 276, 421, having heat detectors responsive smoke or fire in 340 293 222 297 the building to enable an alarm generator to provide 4 an alarm signal, and an entry circuit having normally 56 R f open and normally closed entry switches for detectin'g 1 venues i an unauthorized entry of the building,'the entry circuit UNITED STATES PATENTS being energized whenever one of the entry switches is 1 operated to enable the alarm generator to provide a gym? different alarm, and the entry circuit further having a 3,449,738 6/1969 Chesnul et al. ..340/274 gg ggg mdcaung when sw'tch 2,637,801 /1953 Kelley et al. ..340/274 UX 3,537,094 10/ 1970 Hawkins et al. ..340/276 22 Claims, 5 Drawing Figures AMP 78 To ,F/RE L 12am TEST $11: 80 WALL 7 HEAT om'cr :3 I4] l4 27 I5! I2 [47 \m outs/0E m 0 l5 uaur 13/ 150 13 l 15 f OUTSIDE uanr I I cor/moi cxr HORN ALARM L02 ENTRY I| SWITCHING 24L c/rr 13 26 err CIRCUIT 2/ ,48 I Z; 43 1 a 40-00 9 30 owners/1 I msrzn CONTROL 33 r0 l/OVAC CIRCUIT I Q I ENTRY 39 23a 35 SYSTEM -36 ENTRY 765 READY SYSTEM on Ih-JZ 8 1 FIRE AND BURGLAR ALARM SYSTEM BACKGROUND OF THE INVENTION 1 Field of the invention This invention relates to security systems and more particularly, to a fire and burglary detection system for providing audio and visual alan'ns in response to the detection of a fire in a building or an unauthorized entry of the building.

2. Discussion of the prior art Security systems generally available are limited to a single detecting function, such as the detection of an entry of a building or a dwelling through the use of entry switches located in window or door casings and operated whenever the window or door is opened by an intruder. Other systems provide warning against fire and include heat detectors located within the building which are responsive to the detection of fire or smok to activate a suitable alarm. V

In burglar alarm systems presently available, it is necessary to check each door and window equipped with an entry detector switch to make sure'that such doors and windows are closed prior to activating'the system in order to prevent inadvertent energization of the alarm system and the'generation of a false alarm. Repeated false alarms may annoy neighbors, and if false alarms are frequently generated, for example, because of failure to detect an open door or window prior to activating the system, the alarm system will become a nuisance and its use will be abandoned.

Burglar alarm system now available employ normally closed entry switches located in selected doors and windows. In general, such switches provide adequate protection; however, in some cases an intruder may gain entry of a building without setting off an alarm, and once inside the guarded premises, the intruder would be able to move about undetected.

More sophisticated systems which employ infrared sensors, optical devices, closed circuit television or the like, and which are capable of providing various monitoring functions tend to become" uneconomical for small businesses or for residential use. Moreover, such systems often employ solid-state circuim to minimize expense and size. However, such circuits are susceptible to RF disturbances, such as are generated by signal transmission, airplanes, etc. Such extraneous noises may enable the circuits causing the system to be energized and a false alarm to be generated.

SUMMARY OF THE INVENTION The present invention provides a security system which affords protection for a building by providing a warning that fire or smoke has been detected, or that an unauthorized entry of the building has been detected. The system produces a fire alarm signal, a steady tone, in response to the detection of fire or smoke, alerting everyone in the building of the fire, or a burglar alarm signal, an intermittent tone, to warn occupants of the building whenever someone is trying to enter the building, is tampering with doors or windows, or that someone has gained entry to the building and has operated an entry detector, such as a mat switch, hidden within the building.

The fire, smoke, and entry detectors of the system are connected to a master control circuit having a control device responsive to the operation of the detectors to energize alarm generating circuitry, also part of the master control circuit. The control switches and function lamps of the master control circuit are mounted on a master control panel.

The master control circuit can also be controlled from locations remote from the master control panel through the use of remote control switches mounted on remote control panels. By way of example, a remote control panel for a residence may be located at a bedside or some other convenient location within the home. The remote panels also include function lamps similar to those on the master control panel. Through the use of remote control panels, the system may be energized to set off an alarm at the first sign or suspicion of danger. The alarm will frighten the intruder and in addition, will alert the neighborhood to call for help.

The remote control equipment mayv further include a key-operated, authorized entry switch located on an outside wall of the protected building to permit the alarm system to be activated fromoutside the building.v

Such a switch installation would include a la p for in dicating when the system is activated. I

As the occupant leaves the building, he notes whether the system is activated or not,.by checking the system on lamp on the master control panel or at one of the remote locations which is equipped with an authorized entry circuit. If the system is activated, it can be deactivated at the master control panel, at any of the remote control panels or-at the authorized entry switch. Thus, an occupant, departing the building is warnedif the system is on prior to opening the door, and can deactivate the burglar system without retuming to the master control panel.

The outside authorized key lock control also provides an indication of a need to deactivate the system prior to entering the building. This control contains tamper-proof circuitry responsive to tampering to cause the burglar alarm to sound regardless of whether or. not the burglar system is activated at the time.

The system includes convenience features such as a system ready lamp located on the master and remote control panels which, when lit, indicates that all protected entrances are closed and that the system may be activated without inadvertently setting off the alarm.

Consequently, it is not necessary to make a routine check of all doors and windows before activating the system. Since the system activate switch is located on the panel, a person aboutto activate the system can tell at a glance whether or not the system is ready to be activated. Thus, false alarms frequently caused by failure to detect an open door or window are virtually eliminated.

A further advantage of the system provided by the present invention is that the system can be operated by the use of normally open or normally closed entry switches or both types of switches. Thus, normally closed switches can be mounted to be operable in response to the opening of a window or a door, and normally open switches, such as mat switches can be hidden within rooms or in passageways to be operated when an intruder steps on a switch.

The system may also include a circuit for flashing existing yard lights or post lamps in response to the detection of a fire or an unauthorized entry.

The security system provided by the present invention employs electromechanical switching devices and accordingly is not susceptible to RP. noise generated in the vicinity of the alarm system.

In a described embodiment, a security system for a building includes a first control circuit having entry detect means operated in response to an unauthorized entry of the building to enable alarm generating means to provide a first alarm signal, and a second control circuit including temperature sensitive means responsive to heat of a temperature in the building in excess of a predetermined temperature to enable the alarm generating means to provide a different alarm signal.

The first control circuit includes normally open and normally closed entry switches, control means operated whenever one of the normally closed switches is opened or one of the normally opened switches is closed to energize the alarm generating means and system ready means for indicating that all the entry switches are unoperated.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic circuit diagram of a control circuit for a master station of a security system provided by the present invention;

FIG. la is a plan view of a master control panel for the master station;

FIG. 2 is a schematic circuit diagram of a control circuit of a remote station and a control circuit of an authorized entry station which permit control of the master control circuit from remote locations;

FIG. 2a is a plan view of a control panel for the remote station; and

FIG. 2b is a plan view of a control panel for the authorized entry station.

DESCRIPTION OF A PREFERRED EMBODIMENT The schematic circuit diagram for a security system provided by the present invention is shown in FIGS. 1 and 2. The system includes a master control circuit including an entry circuit 11 for detecting unauthorized entry of a building, a heat detecting circuit 12 for detecting heat or smoke in the building of a temperature exceeding a predetermined temperature, and alarm generating apparatus 13. The illustrated embodiment also includes an outside light control circuit 100.

Upon detection of an unauthorized entry of the building or of the presence of heat or smoke in the building, an alarm is provided by the alarm generating apparatus 13 which includes a horn l5 and a horn drive circuit 16. As will be shown, the alarm drive circuit 16 is operative to provide discrete alarm signals for the detection of an authorized entry and the detection of fire. In the described embodiment, the alarm generating apparatus 13 also controls a light 105 which may be, for example, an existing porch light or yard light located outside of the building. The outside light will be flashed to provide a visual alarm external to the protected building in response to enablement of either the entry circuit 1 l or the heat detecting circuit 12.

ENTRY CIRCUIT The system is basically energized by power supply 14 providing at its output 18 a DC voltage V supplied by an AC to DC converter 19 which converts voltage from a commercial 110 AC volt supply to a rectified DC voltage, or alternatively supplied by a battery 20. A switching circuit 21 normally connects the output of AC to DC converter 19 to the system and is operative in the event of a failure of the source 19 to connect the battery 20 to the system. In the described embodiment, the magnitude of the DC voltage is twenty volts.

The entry circuit 11 includes a plurality of normally closed switches, such as illustrated switch 30, the switches being serially connected in an enabling circuit for a ready lamp 35 which circuit extends operating source potential V over normally closed contacts 23 and 24, a conductor 26, the normally closed contacts of the entry switches, such as illustrated switch 30, conductors 32 and 33, and the system ready lamp 35 to ground.

Each switch is physically located in a window frame, a door frame, or the like, and is normally closed when the associated window or door is closed. When all the entry switches of the entry circuit 11 are closed, the described series circuit is completed from the voltage source 14 to ground over the path described, and the I ready lamp 35 is lit.

A master control relay 25 is connected to the energizing potential V at the output 18 of the supply l4-for energization via a path which includes conductor 36, activate switch 37, conductor 38, link 207, the winding 41 of relay 25, conductor 43, diode 45, conductor 33, and ready lamp 35 to ground. As will be shown, diode 41 is reverse-biased when the entry circuit 11 is completed, and relay 25 is thus normally disabled.

A system on lamp 3], connected between conductor 39 and ground is lit whenever activate switch 37 is closed to indicate that the system is activated.

Master control relay 25 at its contacts 23 and 48 controls the enablement of alarm apparatus 13, and especially a horn drive or motor circuit 16 including a relay 49, over a circuit which extends from the system source of potential 14 over contacts 23 and 48, contacts 51 and 52, resistor 54, a coil 53 of relay 49 and ground. A capacitor 56 is connected across coil 53.

Motor relay 49 in the motor circuit 16 is slow-tooperate and slow-to-release, and the values of capacitor 56 and resistor 54 are chosen to provide the desired operate and release times for the relay 49. when relay 49 operates after an operate delay determined by resistor 54, an energizing circuit for the horn 15 is completed from the energizing source 14 which now extends over contacts 58 and 51 resistor 60 through the horn 15 to ground.

After a time delay, the length of which is determined by capacitor 56, motor relay 49 restores to open contacts 58 and 51 and disable the horn, and to reclose contacts 51 and 52 and re-establish its own energizing circuit.

The motor circuit thus enabled by the master control relay 25 effects intermittent energization of the horn 15 for the period the master relay 25 is energized. Moreover the energizing potential on contact 58 which enables the horn 15 is also extended over conductor 61 to a terminal 141 to which may be connected an outside light control circuit as will be described in detail hereinafter.

Additional, remotely located, horns and bells may also be connected to terminal 141 for receiving an energizing potential.

A manual alarm switch 69 is connected to extend the system potential V from the voltage source 14 over conductor 67 to the drive circuit 16 to thereby permit an alarm to be sounded manually for testing or functional purposes. Thus, if an intruder successfully eludes detection by the entry circuit, the alarm may be set off manually.

The entry system activate switch 37, the manual alarm switch 69, the system on lamp 31, and the system ready lamp 35, which are physically located on a master control panel 70, are shown in FIG. 1a. The master control panel 70 permits convenient access to the controls for the master control circuit and serves to mount the indicator lamps 31 and 35 adjacent the control switches 37 and 69.

OPERATION OF THE ENTRY CIRCUIT The entry circuit 11 of the master control circuit is deactivated whenever activate switch 37 is open; that is, during certain times of the day that the building is normally occupied or whenever it is not necessary to have the system enabled, the activate switch 37 is left open.

When the system is ready to be activated, ready lamp 35 is lit indicating that all doors and windows, etc., equipped with an entry switch, such as switch 30 are closed. If the ready lamp 35 is not lit, a check must be made of all the doors, windows, etc., having an entry switch prior to operation of the activate switch 37. When all of the entry switches are closed, the ready lamp 35 will be enabled by a circuit extending from voltage source 14 over contacts 23 and 24, conductor 26, the entry switches 30, conductors 32 and 33 and lamp 35 to ground, whereby ready lamp 35 is lit and the master control circuit 10 can be safely activated by closing activate switch 37 without causing a false alarm.

When the activate switch 37 is closed, the potential V from the output 18 of the source 14 is also extended over a path which includes conductor 36, switch 37, link 207, and conductor 39 to the winding 41 of master control relay 25, and the system on lamp 31, connected between conductor 39 and ground, will light.

Relay which has one end of its winding 41 connected to conductor 39 and its opposite end connected over diode 45 to ready lamp 33 and to ground will not be energized when system is activated assuming all entry switches, such as switch 30, are closed because the switches conduct the voltage V on conductor 26 to conductor 32 to reverse-bias diode 45. Thus, when the entry switches, such as switch 30 are closed to complete a series circuit to lamp 35, the relay 25 is disabled, even though the system is activated to a nonpower consuming state of readiness by closing switch 37.

In response to an unauthorized entry of the protected building and the opening of an entry switch, such as switch 30, responsive to opening of a door, window,

etc., the reverse bias is removed from the cathode of diode 45, permitting the ground potential to be extended through ready lamp to the coil 41 of relay 25 which then operates.

The system may also include a further detector, such as a mat switch 30 or the like located within the building or residence which may be a normally open switch, for example, and which, when closed, connects a ground to one side of the relay winding 41 to operate the relay 25. The flexibility of the basic system is significantly enhanced by the provision of a control circuit which permits the use of either normally open or normally closed switches for sensing or detecting purposes.

When relay 25 operates, +V is extended over contacts 23 and 48, and contacts 51 and 52 to the winding 53 of relay 49 to operate motor relay 49. As noted heretofore, motor relay 49 is slow to operate due to the resistor 54. When relay 49 operates, the potential V at its contact 51 is switched from its contact 52 to another contact 58 and extended to the horn 15 to energize the horn so that an audible tone is produced. However. when relay 49 operates, the energizing potential is removed from its contact 52 when contacts 51 and 52 are opened, and accordingly capacitor 56 begins to discharge through winding 53 of the relay 49.

After a time determined by the value of capacitor 56 motor relay 49 releases opening contacts 51 and 58 of the relay so that the energizing voltage is removed from the horn and the audible signal is no longer produced. In-addition the energizing potential is applied to capacitor 56 charging capacitor 56 to a potential sufficient to reoperate relay 49, and relay 49 at its contacts 51 and 58 will be operable to energize the born a second time. This motor operation will continue to energize the horn intermittently until the system is deactivated by opening switch 37.

It should be noted that when master relay 25 is operated in response to the opening of the switch 30 (or the closing of switch 30'), contacts 23 and 24 of relay 25 are opened to interrupt the potential V to the entry switches 30. Consequently, even if switch 30 were to be subsequently closed, as for example, by an intruder closing the door by which he had entered, the potential for backbiasing diode 45 to thereby disable master relay 25 has been removed and relay 25 will remain operated to maintain the alarm circuit 13 energized. The alarm signal willcontinue to be generated until the activate switch 37 is opened to interrupt positive potential to relay 25, and permit the master control relay 25 to restore.

MANUAL ALARM The master control circuit 10 further includes a manual alarm or test switch 69 which when closed effects the energization of the alarm drive circuit 13 by extending the voltage from the source 14 through the alarm switch 69 and contacts 51 and 52 of the relay 49 to winding 53, operating relay 49. This feature permits the alarm circuit to be energized and an alarm to be sounded at the first sign of suspicion or danger.

As will be described hereinafter, the system also can be controlled through the use of remote controls located in positions remote from the master control circuit 10. Accordingly, a manual alarm switch similar to alarm switch 69 but located on a remote control panel can also be used to energize its system and sound the alarm from a position remote from the master control station. Once energized from a remote station, the alarm cannot be turned off anywhere except at the remote station from which the alarm has been initiated.

HEAT DETECTING CIRCUIT The heat detecting circuit 12 includes a drive relay 63 having a winding 62 with one end connected to the voltage source 14 over a path which includes a diode 74 and conductors 73 and 67. This end of the winding is also coupled to ground through a capacitor 82.

The other end of the winding is connectable to ground through a heat or smoke sensing device, such as illustrated device 17, which comprises a normally open switch. The sensing device is operative in response to sensing heat or smoke in excess of a temperature for which the device is rated to close a path to ground for the winding permitting the relay 63 to operate.

A plurality of heat or smoke sensing devices, such as illustrated device 17, are generally located throughout the protected building, and each such sensing device is connected in parallel with the illustrated device 17 in the heat detecting circuit 12.

The drive relay 63 includes a pair of normally open contacts 65, 66 operated whenever relay 63 is energized in response to operation of device 17. The contacts 65, 66 are connected to extend energizing potential from the source 14 over a path which includes conductors 67, 73 and 79, the contacts 65, 66, conductor 61 and resistor 60 to the horn 15.

The operate potential extended to the horn 15 over the contacts 65, 66 of drive relay 63 when the relay 63 is energized is also extended to terminal 141 of the master control circuit which is connected to contact 66 of the relay 63. Accordingly, when the outside light control circuit 100 is connected to the master control circuit, that is, when terminal 142 is connected to terminal 141, the potential extended to contact 66 whenever a fire is detected will energize the light control circuit 100 causing lamp 105 to be lit intermittently to provide a visual alarm outside of the protected building.

A lamp 78 and a test switch 80 are connected across conductors 76 and 77 in parallel with the illustrated detecting device 17.

Referring to FIG. 1a, the master control panel further serves to mount the heat detect system on lamp 76 and the system test switch 80.

OPERATION OF HEAT DETECTING CIRCUIT The energizing potential +V is extended to conductor 77 of the heat detecting current 12 whenever power is supplied to the system by converter 19 or the battery 20 and the lamp 78 is lit to indicate the heat detect circuit 12 is activated.

The heat detect circuit 12 is operative to cause a tire alarm to be provided whenever the temperature of the protected building exceeds the temperature rating of the heat sensor 17. When the detector 17 is activated in response to heat, a short circuit is provided between conductors 76 and 77, and ground is connected to one end of winding 62 of relay 63 to operate relay 63 which at its contacts 65 and 66 closes a path from the source 14 to the horn over conductors 67, 73 and 61 and resistor 60 so that the horn is energized and a continuous audio tone is provided. The alarm will not stop until the heat or smoke condition has been eliminated, or the system is deactivated by opening of the power switch (not shown) to the converter 14.

The system test switch 80, connected in shunt with lamp 78, permits manual testing of the system. When the switch is closed, the ground is extended to one end of the winding 62 of relay 63 to operate the relay as described above and operate potential is extended over contacts 65, 66 to energize the horn 15 such that a continuous audio tone is provided. The first test switch 80 thus enables the alarm to be manually activated either in an emergency or for test purposes.

OUTSIDE LIGHT CONTROL An outside light control circuit shown in FIG. 1 permits control of a light located on the outside of the building to provide a visual alarm for the system. The outside light control circuit 100 may control for example, a porch light, a post lamp, yard lights, etc., for use in the normal manner and additionally to flash intermittently in the event of detection of fire or an unauthorized entry condition to provide a visual alarm outside of the protected building.

The lamp control circuit 100 includes a switch relay and a slave relay 1 14 having contacts serially connected in a line voltage circuit (generally a Volt [5 amp circuit) which energizes the lamp 105.

Referring to the schematic of the outside light control circuit 100, shown in FIG. 1, power for energizing the lamp 105 is provided at input terminals 101 and 102 which are connected to a 120 volt, 15 amp circuit. An energizing circuit for normal usage of lamp 105 extends from input terminal 101 over lead 103 through the lamp 105 and back to the other input terminal 102 through normally closed contacts 111 and 112 of the slave relay 114 and normally open contacts 107 and 108 of switch relay 110. Relay 110 which completes the energizing circuit for the lamp 105 is connected in a series circuit including a winding 1 15 of relay 110, and a wall switch 119 connected between terminals 101 and 102. When the wall switch 119 is closed, relay 110 is energized, and the light 105 is turned on.

Slave relay 114 and an alarm relay 120 are controlled by the master control circuit 10 and operate somewhat as a flip-flop to alternately energize and deenergize the light 105 in response to an alarm condition. One end of the winding 122 of slave relay 114 is connected via conductors 124 and 103 to terminal 101. The other end of coil 122 is connectable via a conductor 126, normally opened contacts 127 and 128 of relay 120 and a conductor 129 to terminal 102.

Terminal 142 of the light control circuit 100 would be connected to terminal 141 of the alarm generating circuit to receive an energizing potential there from whenever an alarm is to be provided.

Positive voltage V provided via contacts 65 and 66 of relay 63 of the alarm circuit 13 is extended from terminal 142 over a path which includes conductor 141', diode 143, conductor 144, normally closed contacts 145 and 146, a resistor 147, and winding 130 of relay 120 to ground.

A timing capacitor is connected across winding 130. A filter capacitor 151 is connected between conductor 144 and ground, to provide a constant DC voltage for operating the relays of the light control circuit 100 when the incoming voltage V is intermittent as during a burglar alarm signal.

When the wall switch 119 is not operated, intermittent operation of slave relay 114 provides a circuit opening and closing over its contacts 112 and 149 to flash the lamp 105. Alternately, when wall switch 119 is closed and relay 110 is operated, relay 114 will be operative at its contacts 111 and 112 to open the energizing path for lamp 105 provided by contacts 111 and 112, thereby intermittently turning off the lamp 105.

OPERATION OF OUTSIDE LIGHT CONTROL CIRCUIT When the wall switch 119 is open, lamp 105 is normally turned off. When the master control circuit 10 is energized to effect the generation of an alarm signal and operate relay 62 as described above, relay 62 at its contacts 64 and 65 extends the voltage V from the supply 14 through diode 143, charging capacitor 151, and to the normally closed contacts 145 and 146 of slave relay 114 and resistor 147 to effect the operation of alarm relay 120. Relay '120 is slow to operate because of the resistor 147 connected in series with capacitor 150. Capacitor 150 charges to the pull-in voltage of relay 120 which operates completing the circuit, at its contacts 127 and 128 for relay 114 which circuit extends from terminal 102 over winding 122 and conductor 103 to tenninal 101 to operate relay 114 which, at its contacts 149 and 112, connects terminal 102 through the normally closed contacts 107 and 105' of relay 110 to the lamp 105, turning on the lamp.

When slave relay 114 is operated, its contacts 145 and 146 connected in series with winding 130 of alarm relay 120 are opened, effecting deenergization of relay 120. The capacitor 150 connected in parallel with winding 130 of relay 120 renders the relay slow-torelease. When relay 120 releases, after a predetermined time, the energizing path for winding 122 of relay 114 is opened at the contacts 127 and 128 of relay 120 causing relay 114 to be deenergized, and the lamp 105 to be turned off when contacts 112 and 149 are opened.

Briefly summarized, with the wall switch 119 open, each time relay 120 is operated, relay 1 14 operates and lamp 105 is turned on. In response to the operation of relay 114, relay 120 is deenergized thereby deenergizing relay 114 and causing lamp 105 to be turned off. This cycle will be repeated providing intermittent flashing of the lamp 105 as long as relay 63 remains energized.

Altemately, whenever the wall switch 119 is closed, relay 110, having its winding 115 connected in series with the wall switch 119, is operated, and lamp 105 is energized over a path which extends from terminal 102 over contacts 107 and 108 of relay 110 and contacts 111 and 112 of relay 114, the filament of lamp 105, conductor 103 to terminal 101.

When alarm relay 120 is operated in response to the energization of the master control circuit 10, slave relay 114 is operated in the manner described above and at its contacts 111 and 112 opens the energizing path for lamp 105. As relays 120 and 1 14 are alternately energized and deenergized as described, lamp 105 is turned on and off, the light being intermittently flashed in this manner as long as the master control circuit is energized to provide an alarm. It is pointed out that the lamp is flashed intermittently for both a fire alarm and a burglary alann. 7

It is apparent that an energizing potential can be extended to terminal 141 to control the lamp drive circuit 100 for providing an alarm through the use of other types of switching devices such as semiconductor 1 switching elements, or that the ground potential shown connected to one end of the winding 130 of relay can be switched rather than the potential V which, in the embodiment described above, is extended to the winding 130. For example, a relay or other switching device can be connected to switch the ground to winding only when an alarm is to be provided, and terminal 141 can be connected directly to a potential V. The ground switching device can be controlled by the potential at the output of the alarm generating circuit 16.

CONTROL OF MASTER CIRCUIT FROM REMOTE POSITION The master control circuit 10 includes output terminals 201-206 for permitting the addition of remote stations for controlling the master control circuit 10 from locations remote from the location of the master control circuit. Schematic circuit diagrams of a remote station 200 and an authorized entry circuit 300 for permitting remote control of the master control circuit 10 are shown in FIG. 2. The remote station 200 includes control switches 225 and 226 shown mounted on a remote control panel 270 in FIG. 2a to provide functions similar to those of the activate switch 37 and alarm switch 69 of the master control circuit 10. The authorized entry station 300 includes a key operated swtich 325, shown in FIG. 2b mounted on authorized entry panel 370, for permitting the alarm system to be energized or deenergized from the outside of the building by a person having the proper key.

Considering first the remote station 200 the circuit for the remote station 200 for controlling the master control circuit includes a set of input terminals 211-216 which are connected to output terminals 201206 of the master control circuit 10 by conductors 217-222.

When a remote unit such as remote station 200 is connected to the master control circuit 10, the link 207 is removed.

The remote circuit 200 includes a pair of doublepole, double-throw switches 225 and 226 for activating the master control circuit 10 and for energizing the alarm generating apparatus, respectively.

Activate switch 225 has a first movable contact 227 connected to terminal 211 and normally contacting an associated pole 231. Pole 231 is connected to a pole 232 associated with a second movable contact 230 of the switch 225, and to an output terminal 301 of the circuit 200. Contact 230 of switch 225 is connected to input terminal 212 and normally engages an associated pole 229 of the switch 225. Terminal 212 is connected by conductors 218 and 38 to one side of the system activate switch 37 shown in FIG. 1. The other side of the switch 37 is connected by conductor 217 to input terminal 211 of the remote control circuit 200 and to contact 227.

Pole 229 is also connected to a pole 224 associated with contact 227 of switch 225 and via conductor 228 to output terminal 302. Assuming no further remote apparatus is used, terminal 302 is connected to a terminal 303 via link 307 and via conductors 234, 219 and 39 to the winding of master relay 25 Switch 226 has a movable contact 233 connected to input terminal 212, and an associated pole 235 connected to terminal 21 1. A second movable contact 236 of switch 226 is connected over conductor 237 to input terminal 214 which, via conductors 220 and 238 is connected to winding 41 of master relay 25.

A pole 239 associated with contact 236 of switch 226 is connected by a conductor 240 to an input terminal 216 which is connected via conductor 222 to an output terminal 206 of the master control circuit 10. Terminal 206 is connected to ground.

A ready lamp 241 has one lead connected to ground via conductors 244 and 222 and its other lead connected to entry switch 30 of the master control circuit via conductors 242, 221, and 245. Lamp 241 provides a ready indication similar to that provided by ready lamp 35 of the master control circuit 10 when the entry circuit 1 l of the master control circuit 10 is deenergized.

Activate lamp 246 has one lead connected via conductor 234 to input terminal 213 and via conductors 219 and 39 is connected to the winding 41 of relay 25. The other lead of lamp 246 is connected to ground via conductors 244 and 222. Lamp 246 is connected in parallel with the system activate lamp 31 of the master control circuit 10 and is lit whenever the system is activated.

The remote control station 200 includes output terminals 301-306, to which further remote control equipment in this described embodiment, a remote authorized entry circuit 300 including a key-operated switch 325, a tamper switch 326 and a system on lamp 346, can be connected to the master control circuit 10. If the remote authorized entry circuit 300 (or other remote equipment) is not used, terminals 302 and 303 are connected together, for example by a link 307.

The switches 225 and 226, and indicator lamps 241 and 246 are conveniently mounted on the remote control panel 270 shown in FIG. 2a. Similarly, switches 325 and 326, and indicator lamp 346 of the authorized entry circuit 300 are mounted on an authorized entry switch panel 370 shown in FIG. 2b.

OPERATION OF REMOTE CONTROL SYSTEM In operation, remote activate switch 225 is operative to provide a bypass circuit around the normally open system activate switch 37 of the master control circuit 10. Switch 226 permits manual energization of the alarm apparatus and is similar in function to switch 69.

Assuming the master control circuit is not activated, voltage V from the source 14 is extended via conductors 36 and 217 to input terminal 211 of remote circuit 200, and via contact 227 and pole 231 to terminal 301.

When all of the entry switches, such as switch 30, are closed, the voltage V from the supply 14 is extended over contacts 23 and 24 of relay 25, contacts of the switch 30, conductors 245, 221 and 242 to the ready lamp 241. Thus lamp 241, as well as lamp 35, are lit indicating the system is ready to be activated.

Upon operation of the remote system activate switch 225, contact 227 is connected to pole 224, extending the voltage V from the source 14 appearing at contact 227 via conductor 228, link 307, and conductors 234, 219 and 39 to system on lamp 31 and to the master relay 25. Thus the system activate lamps 31 and 246 of both the master control circuit 10 and the remote control circuit 200 will be turned on by this voltage. Moreover, it is also pointed out that when the master circuit is activated by closing switch 37, the remote system on lamp 246, as well as lamp 31 of the master circuit 14, will be lit, indicating at both locations that the system is activated.

Switch 2.25 thus bypasses switch 37 so that the system is activated to permit energization of the relay 25 if an entry switch 30 or 30' is operated in response to an unauthorized entry as described above with reference to the master control circuit 10.

When the manual alarm operate switch 226 is operated, a connection is provided via contact 233 and pole 235 between terminals 211 and 212 of the remote control circuit, bridging the activate switch 37 of the master control circuit 10, to activate the system if the system is not activated, in addition, a ground extended to terminal 239 via conductors 240 and 222 is further extended via contact 236, and pole 239 of switch 226, and conductors 237, 220 and 238 to the winding 41 of relay 25, causing the relay to operate. Operation of relay 25 effects the energization of circuit 16 and the alarm is sounded.

lt is pointed out that when the alarm is turned on manually by operating either switch 69 or switch 26, the alarm cannot be turned off at a different location but must be turned off by opening either switch 69 or switch 226, whichever is operated. Thus, if the energization of the alarm generating apparatus 16 is effected from the remote position of circuit 200, the alarm cannot be turned off at the master station 10.

AUTHORIZED ENTRY CIRCUIT The authorized entry switch 300, operated by a key 372, is shown in FIG. 2b mounted by way of a face plate 371 on the outside of the protected building to permit activation or deactivation of the master control circuit from outside of the building. To guard against tampering with the externally located switch, a tamper switch 326 is provided. The tamper switch which is positioned behind the face plate, is a normally unoperated springloaded switch. The tamper switch is operated whenever someone attempts to remove the face plate 371. The tamper switch when operated effects sounding of an alarm whether or not the system is activated at the time.

The authorized entry circuit 300 includes terminals 31 1-316 connected to terminals 301-306 of the remote station by conductors 317-322, respectively.

The key switch 325 is a double-pole, double-throw switch similar to switch 225 of the remote station 200. Switch 325 has a movable contact 327 connected to input tenninal 311 of the circuit 300. Terminal 311 is extended to output terminal 301 of the remote circuit 200 via conductor 317 and over contacts 231, 227 of switch 225 of remote circuit 200 and conductors 217 and 36 to one side of the system activate switch 37, FIG. 1. Contact 327 normally contacts an associated pole 331 when the key switch is unoperated. Pole 331 is connected to pole 332 associated with a second movable contact 330 of the switch, and to an output terminal 401 of the authorized entry circuit 300.

Contact 330 of switch 325 is connected to an input terminal 312 of the authorized entry circuit and this terminal is extended through the remote station circuit via conductors 318 and 228, switch 225, and conductors 218 and 38 to the other side of the system activate switch 37, FIG. 1. Contact 330 normally contacts an associated pole 329 of the switch 325. Pole 329 is connected to a pole 324 associated with contact 327 of the switch, and over conductor 328 to an output terminal 402, and is extended, via link 407, to terminal 403 and over conductors 334, 319, 234 and 39 to the winding 41 of the control relay 25.

If additional elements were to be connected to the system, link 407 would be removed, and the additional remote control circuit would have its leads connected to terminals 401406,

The tamper switch 326 includes a double-pole, double-throw switch similar to switch 226 of the remote station. Switch 326 has a movable contact 333 connected to input terminal 312 and an associated pole 335 connected to input terminal 311.

A second movable contact 336 is connected via conductor 337, an output terminal 404 of the authorized entry circuit 300, and thence via conductors 349, 320, 249, 220 and 238 to the winding of master relay 25 of the master control circuit 10. A pole 339, associated with movable contact 336, is connected to ground via conductors 340, 344, 322, 244 and 222.

A system activated lamp 346 is connected in parallel with lamps 31 and 246 between conductor 39 and ground. Lamp 346 has one lead connected via conductors 334, 319, 234, 219, to conductor 39, and its other lead connected to ground over conductors 344, 322, 244 and 222.

OPERATION OF AUTHORIZED ENTRY CIRCUIT Switch 325 is similar in function to switch 225 of the remote station 200 and, when operated, provides a bypass for switch 37 of the master control circuit 10.

Assuming the master control circuit is not activated, the individual who wishes to activate the system checks the master control panel 70 or the remote control panel 270 as he is leaving the building, to insure that the system is ready to be energized as indicated by ready lamps 241, or 35 which will be lit.

To activate the system from outside of the building, the individual having the key 372 for the switch 325 inserts the key into the lock 373 shown in FIG. 2b and by turning the key, operates switch 325.

When switch 325 is operated, contacts 327 and 330 are moved into contact with poles 324 and 332, respectively. At contact 327 of switch 325, the voltage V extended from the supply 14 over conductors 36 and 217 and 317 to contact 327 is passed via conductor 328, link 407 conductors 334, 319, 234, 219, and 39 to the winding 41 of master relay 25. The potential on these conductors will cause system activated lamps 31, 246 and 346 to be lit to indicate that the system is activated. When the system is activated, any unauthorized entry will cause the alarm to be sounded.

If someone tampers with the authorized entry switch by attempting to remove the face plate 371 to disable the activate switch 325, the tamper switch 326 will be operated and contact 333 will engage pole 335 connecting terminals 311 and 312 together, providing a bypass circuit around activate switch 37 of the master control circuit. Thus, when the master control circuit 10 is not activated, the operation of the tamper switch 326 effects activation of the master control circuit.

The second contact 336 of the tamper switch 326 engages pole 339 when the switch is operated by reason of an intruder attempting to disable the switch, and a ground present at pole 339 via conductors 340, 344, 322, 244 and 222 is extended over conductors 337, 349, 320, 249, 220 and 238 to the winding 41 of the relay 25, enabling the master relay 25 which, when enabled, energizes the alarm drive circuit 16 as described above.

Whenever the master control circuit is energized in response to operation of the tamper switch 326, the system power must be turned off, to stop the alarm signal, by disconnecting the vac and the battery, or face plate 371 must be resecured.

If the master control circuit 10 is energized due to operation of either the activate switch 37 or switch 225, the master control circuit can be deenergized by operating the authorized entry switch 325. When the master control circuit is activated at switch 37, an activate path from the source 14 includes conductor 36, switch 37, conductors 38 and 218, contact 230, pole 229, conductors 228, and 318, to contacts 330, and pole 329 of switch 325, conductor 328, link 407, conductors 334, 319, 234, 219 and 39 to the winding of relay 25. The disabling potential is conducted from source 19 over contacts 23 and 24 through the entry circuit 11 to reverse bias diode 45 to prevent operation of relay 25.

When switch 325 is operated the series circuit is opened at contact 330 and pole 329 of switch 325 and the operate potential is no longer extended to relay 25 It can also be shown that when the remote switch 225 is operated, a similar path including contact 227 and pole 224 of switch 225 which includes contact 330 and pole 329 of switch 325 is provided.

Accordingly, the authorized entry circuit 300 can also be used to deactivate the master control circuit when the circuit 10 is activated from within the buildmg.

What is claimed is:

1. In a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, control circuit means including a control relay operable when energized to effect energization of said alarm generating means to provide an alarm, said control relay having a winding with first and second ends, means for connecting the first end of said winding to a point of energizing potential, current rectifier means and indicator means connected in a series circuit path between the second end of said winding and a point of reference potential for providing an energizing path for said control relay, and entry switch means having a normally closed switch connected between said current rectifier means and said point of energizing potential for extending said energizing potential to said current rectifier means to reverse bias said current rectifier means whenever said switch is unoperated to thereby interrupt said energizing path, said switch being operated in response to an unauthorized entry of said building to enable the second end of the winding of said control relay to be connected to the point of reference potential over said series circuit path whereby said control relay is operated to affect energization of said alarm generating means.

2. A security system as set forth in claim 1 in which said alarm generating means include signal generating means and drive circuit means controlled by said control relay for providing an intermittent drive signal for said signal generating means.

3. A system as set forth in claim 2 which includes further control circuit means including temperature sensitive means operated responsive to heat or smoke of a temperature in excess of a predetermined temperature for effecting energization of said alarm generating means to provide a different alarm.

4. A system as set forth in claim 3, which includes first manual alarm switch means for manually energizing said alarm generating means to provide said alann, and second manual alarm switch means for manually energizing said alarm generating means to provide said different alarm.

S. A system as set forth in claim 1 in which there is at least one lamp located outside of the building, and which includes lamp drive means controlled by said alarm generating means and operated whenever said alarm generating means are energized to energize said lamp and provide a visual alarm signal external to said building.

6. A system as set forth in claim 5 wherein said lamp drive means includes first switching means operated by said alarm generating means in response to an unauthorized entry to effect energization of said lamp and second switching means operated by said first switching means for disabling said first switching means and effecting deenergization of said lamp, said second switching means being disabled by said first switching means when said first switching means are disabled permitting said first switching means to be reoperated by said alarm generating means and said lamp to be reenergized, whereby an intermittent drive is provided for said lamp.

7. A system as set forth in claim 6 in which said lamp drive means includes third switching means for manually energizing said lamp, said first and second switching means being effective to override said third switching means in response to an unauthorized entry.

8. A system as set forth in claim 1 in which said entry switch means comprise authorized entry switch means including key-operated switch means for activating said control circuit from the outside of said building.

9. A system as set forth in claim 8 in which said authorized entry switch means further include tamper switch means responsive to tampering to effect the energization of said alarm generating means.

10. A system as set forth in claim 9 in which said tamper switch means include first switch means for activating said control circuit, and second switch means operative to energize said control means when said control circuit is activated to effect energization of said alarm generating means.

11. A system as set forth in claim 1 wherein said entry switch means includes a further normally open switch connected between said second end of said winding and said point of reference potential to provide a further energizing path for said control relay whenever said further switch is operated.

12. In an alarm system, alarm means, relay means including means for energizing said alarm means, a control circuit for selectively enabling said relay means comprising an energizing circuit including said relay means, rectifier means, and resistance means connected in series across a source of potential, and entry switch means for normally shunting said energizing circuit including at least one make-break circuit switch which has a first position for completing a shunt path across said relay means and said rectifier means and extending a potential to reverse bias said rectifier means to thereby interrupt said energizing circuit for said relay means whenever said switch is in said first position, and which has a second position for interrupting said shunt path and the reverse bias potential for said rectifier means to thereby enable said energizing circuit to be completed and said relay means to be energized.

13. An alarm system as set forth in claim 12 in which said resistance means comprises an indicator lamp and said energizing circuit includes a second circuit makebreak switch operable to activate said control circuit.

14. A system as set forth in claim 13 which includes remote manual alarm switch means connected to said control circuit for manually energizing said alarm means from a remote location, the deactivation of said control circuit by said second make-break-switch being ineffective to deenergize said alarm means whenever said remote manual alarm switch means are operated.

15. A system as set forth in claim 13 in which said energizing circuit includes remote switch means for activating said control circuit from a remote location.

16. A system as set forth in claim 15 which includes means for indicating at said control circuit and at said remote location that said control circuit is activated.

17. An alarm system as set forth in claim 12 wherein said relay means includes a contact connected in series with said make-break circuit switch across said relay means.

18. in a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, and control circuit means including control means operable when energized to effect the energization of said alarm generating means, energizing means for providing a series circuit energizing path for said control means, including rectifier means connected in series with said control means across a source of potential, and entry switch means for providing a normally closed shunt circuit path for a portion of said energizing path said shunt circuit path including at least one normally closed entry switch which is connected across said control means and said rectifier means to extend a potential for reverse biasing said rectifier means whenever said entry switch is closed whereby said energizing path is normally interrupted and said control means is normally deenergized, said entry switch being operable in response to an unauthorized entry of said building to open said shunt circuit path enabling said control means to be energized.

19. A system as set forth in claim 18 in which said entry switch means includes a further switch means for providing a normally open energizing circuit path for said control means, said further switch means being operable in response to an unauthorized entry of said building to effect the energization of said control means.

20. In a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, a control circuit including control means operable when energized to effect the energization of said alarm generating means, energizing means including remote switch means for providing a series circuit energizing path connecting said control means to a source of potential for energizing said control means, and entry switch means including means for providing a normally closed shunt circuit path for a portion of said energizing path to maintain said control means disabled, said entry switch means being operable in response to an unauthorized entry of said building to open said shunt circuit path to thereby enable said control means to be energized, said remote switch means being operable to activate said control circuit from a remote location to enable said control means to be energized responsive to operation of said entry switch means.

21. A system as set forth in claim 20 in which said remote switch means include authorized entry switch means having key-operated switch means for activating said control circuit from outside of said building, indicator means for indicating when said control circuit is activated, and tamper switch means responsive to tampering to activate said control circuit and to effect energization of said control means whereby said alarm generating means is energized to provide said alarm.

22. In a security system for a building, alarm generating means including signal generating means, first drive circuit means for said signal generating means including self interrupting switching means operable when said first drive circuit means are energized to energize said signal generating means intermittently to provide a first alarm, second drive circuit means operable when enabled to energize said signal generating means continuously to provide a second alarm, a first control circuit including control means operable when enabled to effect the energization of one of said drive means to provide one of said alarms, normally closed entry switch means operable in response to an entry of said building while said first control circuit is activated to enable said control means to be energized, a second control circuit including temperature sensitive means operated responsive to heat or smoke of a temperature in excess of a predetermined temperature for effecting the energization of the other of said drive circuit means to provide said other alarm, first manual alarm switch means for permitting manual energization of said first drive means and second manual alarm switch means for permitting manual energization of said second drive means. 

1. In a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, control circuit means including a control relay operable when energized to effect energization of said alarm generating means to provide an alarm, said control relay having a winding with first and second ends, means for connecting the first end of said winding to a point of energizing potential, current rectifier means and indicator means connected in a series circuit path between the second end of said winding and a point of reference potential for providing an energizing path for said control relay, and entry switch means having a normally closed switch connected between said current rectifier means and said point of energizing potential for extending said energizing potential to said current rectifier means to reverse bias said current rectifier means whenever said switch is unoperated to thereby interrupt said energizing path, said switch being operated in response to an unauthorized entry of said building to enable the second end of the winding of said control relay to be connected to the point of reference potential over said series circuit path whereby said control relay is operated to affect energization of said alarm generating means.
 2. A security system as set forth in claim 1 in which said alarm generating means include signal generating means and drive circuit means controlled by said control relay for providing an intermittent drive signal for said signal generating means.
 3. A system as set forth in claim 2 which includes further control circuit means including temperature sensitive means operated responsive to heat or smoke of a temperature in excess of a predetermined temperature for effecting energization of said alarm generating means to provide a different alarm.
 4. A system as set forth in claim 3 which includes first manual alarm switch means for manually energizing said alarm generating means to provide said alarm, and second manual alarm switch means for manually energizing said alarm generating means to provide said different alarm.
 5. A system as set forth in claim 1 in which there is at least one lamp located outside of the building, and which includes lamp drive means controlled by said alarm generating means and operated whenever said alarm generating means are energized to energize said lamp and provide a visual alarm signal external to said building.
 6. A system as set forth in claim 5 wherein said lamp drive means includes first switching means operated by said alarm generating means in response to an unauthorized entry to effect energization of said lamp and second switching means operated by said first switching means for disabling said first switching means and effecting deenergization of said lamp, said second switching means being disabled by said first switching means when said first switching means are disabled permitting said first switching means to be reoperated by said alarm generating means and said lamp to be reenergized, whereby an intermittent drive is provided for said lamp.
 7. A system as set forth in claim 6 in which said lamp drive means includes third switching means for manually energizing said lamp, said first and second switching means being effective to override said third switching means in response to an unauthorized entry.
 8. A system as set forth in claim 1 in which said entry switch means comprise authorized entry switch means including key-operated switch means for activating said control circuit from the outside of said building.
 9. A system as set forth in claim 8 in which said authorized entry switch means further include tamper switch means responsive to tampering to effect the energization of said alarm generating means.
 10. A system as set forth in claim 9 in which said tamper switch means include first switch means for activating said control circuit, and second switch means operative to energize said control means when said control circuit is activated to effect energization of said alarm generating means.
 11. A system as set forth in claim 1 wherein said entry switch means includes a further normally open switch connected between said second end of said winding and said point of reference potential to provide a further energizing path for said control relay whenever said further switch is operated.
 12. In an alarm system, alarm means, relay means including means for energizing said alarm means, a control circuit for selectively enabling said relay means comprising an energizing circuit including said relay means, rectifier means, and resistance means connected in series across a source of potential, and entry switch means for normally shunting said energizing circuit including at least one make-break circuit switch which has a first position for completing a shunt path across said relay means and said rectifier means and extending a potential to reverse bias said rectifier means to thereby interrupt said energizing circuit for said relay means whenever said switch is in said first position, and which has a second position for interrupting said shunt path and the reverse bias potential for said rectifier means to thereby enable said energizing circuit to be completed and said relay means to be energized.
 13. An alarm system as set forth in claim 12 in which said resistance means comprises an indicator lamp and said energizing circuit includes a second circuit make-break switch operable to activate said control circuit.
 14. A system as set forth in claim 13 which includes remote manual alarm switch means connected to said control circuit for manually energizing said alarm means from a remote location, the deactivation of said control circuit by said second make-break-switch being ineffective to deenergize said alarm means whenever said remote manual alarm switch means are operated.
 15. A system as set forth in claim 13 in which said energizing circuit includes remote switch means for activating said control circuit from a remote location.
 16. A system as set forth in claim 15 which includes means for indicating at said control circuit and at said remote location that said control circuit is activated.
 17. An alarm system as set forth in claim 12 wherein said relay means includes a contact connected in series with said make-break circuit switch across said relay means.
 18. In a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, and control circuit means including control means operable when energized to effect the energization of said alarm generating means, energizing means for providing a series circuit energizing path for said control means, including rectifier means connected in series with said control means across a source of potential, and entry switch means for providing a normally closed shunt circuit path for a portion of said energizing path said shunt circuit path including at least one normally closed entry switch which is connected across said control means and said rectifier means to extend a potential for reverse biasing said rectifier means whenever said entry switch is closed whereby said energizing path is normally interrupted and said control means is normally deenergized, said entry switch being operable in response to an unauthorized entry of said building to open said shunt circuit path enabling said control means to be energized.
 19. A system as set forth in claim 18 in which said entry switch means includes a further switch means for providing a normally open energizing circuit path for said control means, said further switch means being operable in response to an unauthorized entry of said building to effect the energization of said control means.
 20. In a burglar alarm system for providing an alarm in response to the detection of an unauthorized entry of a building, said system comprising alarm generating means, a control circuit including control means operable when energized to effect the energization of said alarm generating means, energizing means including remote switch means for providing a series circuit energizing path connecting said control means to a source of potential for energizing said control means, and entry switch means including means for providing a normally closed shunt circuit path for a portion of said energizing path to maintain said control means disabled, said entry switch means being operable in response to an unauthorized entry of said building to open said shunt circuit path to thereby enable said control means to be energized, said remote switch means being operable to activate said control circuit from a remote location to enable said control means to be energized responsive to operation of said entry switch means.
 21. A system as set forth in claim 20 in which said remote switch means include authorized entry switch means having key-operated switch means for activating said control circuit from outside of said building, indicator means for indicating when said control circuit is activated, and tamper switch means responsive to tampering to activate said control circuit and to effect energization of said control means whereby said alarm generating means is energized to provide said alarm.
 22. In a security system for a building, alarm generating means including signal generating means, first drive circuit means for said signal generating means including self interrupting switching means operable when said first drive circuit means are energized to energize said signal generating means intermittently to provide a first alarm, second drive circuit means operable when enabled to energize said signal generating means continuously to provide a second alarm, a first control circuit including control means operable when enabled to effect the energization of one of said drive means to provide one of said alarms, normally closed entry switch means operable in response to an entry of said building while said first control circuit is activated to enable said control means to be energized, a second control circuit including temperature sensitive means operated responsive to heat or smoke of a temperature in excess of a predetermined temperature for effecting the energization of the other of said drive circuit means to provide said other alarm, first manual alarm switch means for permitting manual energization of said first drive means and second manual alarm switch means for permitting manual energization of said second drive means. 